Device for securing a constant tension and a minimum friction of the warp threads in the manufacture of textiles



June 21, 1960 J. ZMATLI K ETAL 2,941,550

DEVICE FOR SECURING A CONSTANT TENSIQN AND A MINIMUM FRICTION OF THE WARP THREADS IN THE MANUFACTURE OF TEXTILES I 3 Sheets-Sheet 1 Filed Feb. 25, 1958 June 21, 1960 z ETAL 2,941,550

DEVICE FOR SECURING A CONSTANT TENSION AND A MINIMUM FRICTION OF THE WARP THREADS IN THE MANUFACTURE OF TEXTILES Filed Feb; 25, 1958 3 Sheets-$heet 2 INVENTORS .7bxe/Zma7/fl )fZi/ag/mr 77:71

- June 21, 1960 zMATLlK EIAL 2,941,550

DEVICE FOR SECURING A CONSTANT TENSION AND A MINIMUM FRICTION OF THE WARP THREADS IN THE MANUFACTURE OF TEXTILES Filed Feb. 25, 1958 3 Sheets-Sheet 3 United States atet 2,941,55 Ice atented June 21, 19

Josef Zmathk, 633 Belocerkevska, and Milcslav 15a,

Trida Vitezneho unora, both of Prague XII, Czecho- Slovakia Filed Feb. 25, 1958, Ser. No. 717,517 Claims priority, application Czechoslovakia Feb. 26, 1957 1 Claim. (Cl. 139-55) The present invention relates to a device for securing a constant tension and a minimum friction of the warp threads during the weaving of textiles.

In existing looms for the weaving of textiles, a constant tension of the warp threads is not obtained, the warp threads being subject to a considerable stress by varying forces and friction during the weaving process.

In the existing looms there is unequal tension on the warp threads during the formation of the shed, and simultaneously there is considerable friction on the warp threads in the eyelets of the heddles. The unequal tension and friction are the cause of warp thread breakages and stoppages of the looms in the production of most types of textile goods. Some materials cannot, for this reason, be manufactured on an industrial scale at all. Moreover, these conditions, which are characteristic of the existing looms, prevent the attainment of high operating speeds and of a force for beating-up the weft, and further make it difiicult to attain sufiicient cleanliness and size of the shed. The described unequal tension and friction on the warp threads also make it impossible to design weaving looms having dimensions and thus of minimum power consumption with mam'mum economic efiiciency.

The above mentioned drawbacks of existing looms are avoided according to the invention, by rendering the tension of all warp threads equal and constant, while the friction of the warp threads in the eyelets of the heddles or shed needles is kept at a minimum, in an arrangement in which the size of the shedangle may be made as large as is desired. The loom according to the invention further makes possible the simultaneous formation of two or more sheds so that, when weaving carpets, tubular goods and thelike, two or more wefts may be inserted at the same time.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following detailed description of an illustrative embodiment of the invention which is to be read in connection with the accompanying drawings forming a part hereof.

In the drawings:

Fig. 1 is a diagrammatic cross sectional view of the shed forming mechanism, compensating rods or whips and back-rest of a loom embodying the invention.

Fig. 2 is a similar view, but showing other portions of the shed, and

Fig. 3 shows a mechanical arrangement for effecting the desired movements of each compensating rod or whip in accordance with the movements of the related shaft of the shed forming mechanism.

In the loom embodying the invention, the harnesses or shafts 1, 2 (Figs. 1 and 2) are provided with heddles 1b, 2b, which have the shape of a circular arc and are provided with eyelets 1c and 2c in their central portions. The centers of the circular arcs of the heddles lie on the line 3b, which corresponds to the weft last inserted into the fabric 3 produced by the warp threads 4 and 5. The warp threads 4 and 5 pass around rotatable compensating rods or whips 6, 7 which are mounted in guides (not shown) to follow paths 8, 9 which have the shape of involutes of the circular cross-section of a rotatable backrest or guide roller 10 under which the warp threads pass.

Fig. 3 shows the frame 11 of the harness or shaft 1 which is mounted for rotation on a pivot 12 and driven by a rod 13 connected to any desired known driving meansperforming a reciprocal movement. Mounted on the frame 11 is a pivot 14, the axis of which lies on the line connecting the centers of the eyelets of the heddles 1b. Arranged on the pivot 14 is a bearing 15, which is rigidly surrounded by a steel strip 16 passed around the related whip or compensating rod 6 and secured to a bearing 10b of the back-rest 10. The bearing 10b has the same circular cross section and axis as the back-rest 10 which is provided with a trunnion 100 for free rotation in the hearing. The compensating rod 6 has a pivot 6b to which is attached the eyelet of a tension spring 17, and

the latter is secured, at its other end, to the frame of the machine and pulls the compensating rod 6 in the direction of the arrow A.

It is to be understood that the harness or shaft 2 has a construction similar to that described above with reference to harness 1 and is similarly connected to the backrest 10 and the related Whip or compensating roll 7.

The described device operates as follows:

The frame 11 of the shaft 1 (Fig. 3) is driven by the reciprocated rod 13, so that shaft 1 oscillates about pivot 12 and the heddles 1b carried by the shaft 1 assume alternately the extreme positions shown in Fig. 1 and in full lines on Fig. 2. The compensating rod 6, pulled by the spring 17, is controlled by the steel strip 16 so that its axis is displaced along the involute path 8 in response to movement of the heddles 1b.

Since drive of the heddles 2b mounted in the shaft 2, and the control of the compensating rod 7 are similar to the described drive of the heddles 1b and control of the compensating rod 6, the compensating rod or whip 7 is also displaced along the involute path 9 in response to movements of the heddles 2b.

Upon a change of the shed, the heddles 1b, 2b, the threads 4, 5 and compensating rods 6, 8 proceed from the position shown in Fig. 1 first to a position represented in Fig. 2 in dotted lines, and finally to the position shown in Fig. 2 in full lines.

Since the eyelets 1c, 20 of the heddles 1b, 2b move along circular paths, the centers of which lie on the line 3b corresponding to the last weft woven into the produced fabric 3, and the axes of the compensation rods 6, 7 move along the paths 8, 9 which follow involutes of a circle identical with the cross-sectional contour of the backrest 10, there is no relative displacement upon formation of the shed at the points of contact of the threads 4, 5 with the heddles 1b, 2b and with the compensating rods 6, 7. The length of the threads 4, 5 between the points of contact of the latter with the heddles and with the compensating rods is permanently constant by reason of the control of the positions of the compensating rods 6, 7 from the frames of shafts 1, 2 by means of the steel strips 16 which, at any moment, assume positions identical with the positions of the warp threads passing through the heddles of the corresponding shafts or harnesses. Since the lengths of the warp threads from the points of contact with the back-rest 10 to the line 3b are not varied during formation of the shed, the tension of all threads remains permanently constant.

When weaving multiweft fabrics or tubular goods, two or more sheds may be produced above each other. Thus, for example, when producing two-weft carpet fabrics and picking pattern Wefts, the threads interlacing above the upper weft produce the upper shed and the threads interlacing below the lower Weft produce the lower shed,

whereas the filling warp and threads interlacing belowthe has a particular arrangement for effecting the desired movements of the compensating rods 6 and 7 along the involute paths 3 and 9 in response to the oscillations of the corresponding shafts or harnesses 1 and 2, it is apparent that other arrangements may be easily provided for similarly relating the movements of the harnesses and the compensating rods or whips so as to ensure constant, uniform tension in all Warp threads.

Thus, although a particular embodiment of the invention has been described; in detail herein with reference to the accompanying drawings, it is to be understood that the; invention is not limited to that precise embodiment, and that various changes and modifications may be efiected therein without departing from the-scope or spirit of the invention, except as defined in the appended claim.

We claim:

In a loom having at least two series of heddles with warp thread receiving eyelets which are oscillated alternately in opposite directions along arcuate paths concentric with the last weft thread woven into a fabric in order to shed the warp threads; the combination of a backrest roll around which the warp threads pass on the way to said heddle eyelets, a compensating roll for each series ofheddles movable generally toward and away from the latter along a path which is an involute of the crosssection of said bac'lerest roll, with the warp threads received by the eyelets of, each of said series of heddles passing around the related compensating roll between said back-rest roll and said heddles, and actuating means for said compensating rolls operating in synchronism with the oscillations of said series of heddles to positively: displace the related compensating rolls along said involute paths so that the length along each warp thread between the points of contact of the latter with, said back-rest roll and with the related heddle eyelets remains constant during shedding of the warp threads, said actuating means including means yieldably urging each compensating roll along the related involute path, in the direction generally away from said heddles, and at least one flexible strip for each compensating: roll attached, at one end, to the related series of heddles to move with the eyelets of the latter and attached, at its other end, to a fixed cylindrical surface which is axially aligned with the surface of said back-rest roll, said flexible strip passing around the related compensating roll so as to follow a path which is identical to the path followed by the-warp threads passing around said related compensating roll.

References Cited in the file of this patent UNITED STATES PATENTS 1,183,583. Moriggl May 16, 1,916.

1,222,524 Chernack Apr. 10,1917

2,090,785 Diederichs r- Aug. 24, 1937 2,638,935 Stortz May 19, 1,953

FOREIGN PATENTS 143.555 Great Britain Apnll, 1921 

